【摘要】 通过室内原状土柱与重塑土柱对比实验,应用溶质穿透曲线研究柑橘地土壤优先流及溶质优先运移的特征。结果表明:柑橘地原状土柱土壤穿透曲线表现出了上升阶段的拐点现象,是优先流与基质流共同作用的结果。原状土柱土体穿透曲线下降初期较陡,并表现出了较长的拖尾特征,重塑土柱下降趋势相对稳定。存在优先路径的土体出流速率稳定性较差,变异系数较大,其平均出流速率是重塑土柱出流速率的3.5倍。优先流作用使溶质相对浓度到达峰值的时间缩短了37.7%,此时造成的溶质运移量却是平衡基质流所造成的溶质运移量的2.5倍,因此优先流能够导致土壤溶质的快速大量迁移。更多还原

【Abstract】 The characteristic of preferential flow and preferential transport was analyzed with undisturbed and packed soil columns applied breakthrough curve(BTC).The result showed the effect of preferential flow and matrix flow was responsible for the turning point in the rising phase of BTC in undisturbed soil column.In the decreasing phase,compared with packed soil column with a relatively steady effluent rate,undisturbed soil column had a long trailing.Preferential flow was the contribution to the less stable of soil effluent rate and coefficient of variation.The average effluent rate of undisturbed soil column was 3.5 times higher than the average effluent rate of packed soil column.Preferential flow shortened the breakthrough time of 37.7% while transported 2.5 times solute higher than matrix flow when the solute relative concentration reaching the peak.Preferential flow can lead a fast mass of soil solute migration.更多还原